Most of the energy used in the world today is derived from the combustion of carbon and hydrogen containing fuels such as coal, oil and natural gas, as well as other organic fuels. Such combustion generates flue gases containing high levels of carbon dioxide. Due to the concerns about global warming, there is an increasing demand for the reduction of emissions of carbon dioxide to the atmosphere, why methods have been developed to remove the carbon dioxide from flue gases before the gas is released to the atmosphere.
WO 2006/022885 discloses one such method of removing carbon dioxide from a flue gas, which method includes capturing carbon dioxide from a flue gas cooled to a temperature below ambient temperature (preferably between 0° C. and 20° C., more preferably between 0° C. and 10° C.) in a CO2 absorber by means of an ammoniated solution or slurry. The CO2 is absorbed by the ammoniated solution in the absorber at a temperature between 0° C. and 20° C., more preferably between 0° C. and 10° C., after which the ammoniated solution is regenerated in a regenerator under elevated pressure and temperature to allow the CO2 to escape the ammoniated solution as gaseous carbon dioxide of high purity.